Template:Digoxin mechanism: Difference between revisions

Latest revision as of 22:30, 12 September 2015

Inhibits Na+/K+ ATPase in the myocardium^[1]
- Causes increase in intracellular sodium levels
- Results in reversal of sodium-calcium exchanger
  - Normally imports three extracellular sodium ions into the cardiac myocyte in exchange for one intracellular calcium being exported
- Sodium accumulates intracellularly and is exchanged for Calcium.
- Causes an increase in the intracellular calcium concentration increasing contractility
  - Also a lengthening of phase 4 and phase 0 of the cardiac action potential which ultimately decreases heart rate
Summary
- Inhibits NaK pump
  - Positive inotropy
- Negative chronotropy/dromotropy
  - Indirect vagal stimulator

↑ Gheorghiade M. et al. Digoxin in the Management of Cardiovascular Disorders. Circulation. 2004; 109: 2959-2964

@@ Line 1: / Line 1: @@
 *Inhibits Na+/K+ ATPase in the myocardium<ref>Gheorghiade M. et al. Digoxin in the Management of Cardiovascular Disorders. Circulation. 2004; 109: 2959-2964</ref>
 **Causes increase in intracellular sodium levels
-**Results in reversal of sodium-calcium exchanger (normally imports three extracellular sodium ions into the cardiac myocyte in exchange for one intracellular calcium being exported)
+**Results in reversal of sodium-calcium exchanger
+***Normally imports three extracellular sodium ions into the cardiac myocyte in exchange for one intracellular calcium being exported
 **Sodium accumulates intracellularly and is exchanged for Calcium.
 **Causes an increase in the intracellular calcium concentration increasing contractility